Improve check order during TypeSpec PR CI runs

[catalinaperalta]

Seems that during CI runs for TypeSpec PRs checks are triggered in batches and several swagger checks run before the TypeSpec Validation check. Ideally the TypeSpec Validation check would be the first one triggered on TypeSpec PRs since that check provides the best first warning for something amiss in the TypeSpec project and can facilitate getting the PR ready for review more quickly.

[lmazuel]

@mikeharder we were wondering if that's easy to decide in what order some jobs are run? To run the TypeSpec required job first if we can.